The Finnish communications giant got its start as a paper company near the town of Nokia not far from the Nokianvirta River. Thus its first logo in 1871 was that of a scary-looking fish. Even though the company got into the communications business in the 1910's, they kept the creepy fish logo until the 1960s.
Steve Hall, who helms the long-running advertising blog Adrants, thinks the change was a wise one. When presented with Nokia's original logo, he said it made him think: "Looks like an interesting restaurant."
Not exactly the reaction you're fishing for when you're in the fiercely competitive cell phone business. So they wisely changed their logo.